Sediment control dam structure

Abstract

The present invention aims to provide a sediment control dam structure that can efficiently remove sediment and rocks accumulated on the dam with a simple structure, thereby reducing the cost of installing access roads and enabling construction in a short period of time. [Solution] The present invention provides a sediment control dam structure comprising: a sediment control dam 10 installed in a stream G to suppress the flow of sediment and rocks downstream; and a management road 20 used for removing and transporting sediment and rocks from the sediment accumulation area S of the sediment control dam 10, wherein the management road 20 has a downstream slope 22 connecting the downstream area D of the sediment control dam 10 and the top surface 12 of the sediment control dam 10.

Description

【Technical Field】 【0001】 Relates to a sand prevention dike structure provided with a management road used for removing stones from sediment deposited in the sediment accumulation area on the upstream side of the sand prevention dike. 【Background Art】 【0002】 As is well known, due to heavy rain and the like accompanying recent climate change, it is expected that the risk of sediment disasters will further increase. Therefore, in order to prevent sediment disasters, measures have been taken to install sand prevention dikes in rivers and streams to suppress the flow of debris flows. It has been pointed out that the installation of such sand prevention dikes may further increase in necessity in the future. 【0003】 Such sand prevention dikes have functions of suppressing the generation of sediment due to river erosion and suppressing the flow of debris flows and the like downstream. As sand prevention dikes, for example, impermeable dikes and permeable dikes have been widely put into practical use (see, for example, FIGS. 16 to 18 of Non-Patent Document 1). And it is necessary to regularly or urgently remove stones from the sediment deposited on the sand prevention dike and empty the planned capture part in order to maintain the ability as a sand prevention dike (see, for example, FIG. 19 of Non-Patent Document 1). 【0004】 Thus, when removing stones from the sediment deposited in the sediment accumulation area on the upstream side of the sand prevention dike, a stone removal plan is made. For example, as shown in the figure on page 5 of "Section 5 Attached Facilities (1) of the 'Divided Edition: Kyoto Prefecture Sand Prevention Technology Standards (Draft) IV Management Edition (February 2021)' Management passage ", it is common to install from the sediment accumulation area of the dike up to near the dike and remove stones (see, for example, the figure on page 5 of Non-Patent Document 2). Management passage 【Prior Art Documents】 【Non-Patent Documents】 【0005】 【Non-Patent Document 1】 https: / / www.pref.gunma.jp / uploaded / attachment / 28701.pdf [Non-Patent Document 2] https: / / www.pref.kyoto.jp / sabo / documents / 20210329_1.pdf 【0006】 However, constructing such access roads requires bypassing the dam from either the right or left bank, excavating the mountainside on a large scale, and forming cut slopes on the mountainside. Therefore, depending on the situation, earthworks equivalent to excavating a large portion of the mountain may be necessary, resulting in long, steep slopes, and requiring measures such as rock bolts or slope protection structures to stabilize the cut slopes. As a result, the construction costs for laying access roads can sometimes be several times higher than those for the dam itself, and it is anticipated that these significant costs and the resulting labor shortage due to the prolonged construction period will need to be addressed. 【0007】 On the other hand, labor shortages in the construction industry are a concern due to changes in the social environment, such as population decline and shorter working hours. In addition, rising material prices and increasing logistics costs are leading to a growing trend in the construction costs of erosion control dams and access roads. 【0008】 Therefore, considering the promotion of disaster prevention measures to cope with debris flow disasters caused by climate change, as well as labor shortages and the resulting rise in construction costs, it is considered necessary to have a sediment control dam structure that can reduce installation costs and be installed in a short construction period. [Overview of the Initiative] [Problems that the invention aims to solve] 【0009】 This invention was conceived based on the aforementioned technical background, and aims to provide a sediment control dam structure that can efficiently remove sediment and rocks accumulated on the dam with a simple structure, thereby reducing the construction costs associated with the installation of access roads and enabling construction in a short period of time. [Means for solving the problem] 【0010】 The present invention is a sand control dike structure comprising a sand control dike installed in a mountain stream or river to suppress the downstream flow of earth, stones, and gravel, and a management road used for removing and transporting the earth, stones, and gravel deposited in the sand storage area of the sand control dike. It is characterized in that the management road Viewed in plan has a downstream road in the downstream area of the sand control dike. It extends in a straight line from there toward the aforementioned sediment control dam, with its upstream end positioned on the crest and formed to allow it to ascend to the crest. Or the downstream road is formed by connecting the downstream area and the non-overflow part of the top edge. The aforementioned non-overflow section is designed to allow ascent. Or the management road The aforementioned access road is, Formed on both the left and right banks of a stream or river, It is characterized by the following: or has an upstream road formed from the top edge and used for carrying out the earth, stones, and gravel from which stones have been removed. Or Towards the rock removal work area in the upstream region the management road is formed of the same material as the sand control dike. Or the sand control dike has a front yard protection structure, the downstream road is constructed with an embankment and has a protection wall installed on the side of the front yard protection structure. Or the top edge has a crane installation part, and a stone-removing crane can be attached to the crane installation part. Or the top edge has a crane installation part, and a stone-removing crane can be attached to the crane installation part. It is characterized by the above. 【Advantages of the Invention】 ​【0011】 According to the sand prevention dike structure of the present invention, by installing a management road on the downstream side of the sand prevention dike and integrating it with the sand prevention dike, it is no longer necessary to form a large-scale cut on the slope of the mountainside for laying the management road, and it is possible to reduce the construction cost and shorten the construction period. 【Brief Description of Drawings】 【0012】 [Figure 1] It is a perspective view for explaining the schematic configuration of a management road integrated sand prevention dike (sand prevention dike structure) according to the first embodiment of the present invention. [Figure 2] It is a conceptual diagram showing a longitudinal section in the center of the water flow indicated by arrow II-II in FIG. 1 for explaining the schematic configuration of a management road integrated sand prevention dike (sand prevention dike structure) according to the first embodiment. [Figure 3] It is a conceptual diagram of the sand prevention dike constituting the management road integrated sand prevention dike (sand prevention dike structure) according to the first embodiment, viewed from the downstream side indicated by arrow III in FIG. 1 for explaining the schematic configuration. [Figure 4] It is a conceptual diagram for explaining the schematic configuration of a crane installation part of a management road integrated sand prevention dike (sand prevention dike structure) according to a modification of the first embodiment. [Figure 5] It is a conceptual diagram of the sand prevention dike constituting the management road integrated sand prevention dike (sand prevention dike structure) according to the second embodiment, viewed from the downstream side for explaining the schematic configuration. 【Modes for Carrying Out the Invention】 【0013】 Hereinafter, referring to FIGS. 1 to 3, a management road integrated sand prevention dike (sand prevention dike structure) according to the first embodiment of the present invention will be described. Figure 1 is a perspective view illustrating the schematic configuration of a road-integrated sediment control dam (sediment control dam structure) for management purposes according to the first embodiment of the present invention; Figure 2 is a conceptual diagram showing a longitudinal section at the center of the water flow indicated by arrow II-II in Figure 1, illustrating the schematic configuration of a road-integrated sediment control dam (sediment control dam structure) for management purposes; and Figure 3 is a conceptual diagram of a sediment control dam that constitutes a road-integrated sediment control dam (sediment control dam structure), viewed from the downstream side indicated by arrow III in Figure 1, illustrating the schematic configuration of the sediment control dam. In the figure, reference numeral 100 indicates the integrated erosion control dam (erosion control dam structure) for the access road, reference numeral 10 indicates the erosion control dam, reference numeral 11 indicates the dam body, and reference numeral 20 indicates the access road. In Figure 1, the right bank is shown with a dashed line to make the general configuration of the integrated erosion control dam (erosion control dam structure) for the access road easier to understand. 【0014】 The integrated erosion control dam (erosion control dam structure) 100, as shown in Figures 1 to 3, comprises, for example, an erosion control dam 10 and an access road 20, and is installed, for example, in a valley (or river) G. 【0015】 The sediment control dam 10 comprises a dam body 11, which is for example a permeable dam, and a forecourt protection structure 16 formed on the downstream side of the dam body 11. In this embodiment, the sediment control dam 10 (dam body 11, forecourt protection structure 16) is formed of, for example, soil cement. 【0016】 Furthermore, the materials used to construct the sediment control dam 10 may be arbitrarily selected. For example, it may be constructed with concrete instead of soil cement, or a combination of soil cement and concrete may be used, or other materials may be used. In addition, reinforcing members such as structural steel or reinforcing bars may be placed inside the sediment control dam 10. 【0017】 As shown in Figures 1 to 3, the main body of the dam 11 has a crest 12 formed at its upper part. Furthermore, the top surface 12 includes a non-overflow section 13 and an overflow section 14. The non-overflow sections 13 are formed on both the left and right sides of the dam body 11, and a portion of them is formed on the upper surface of the sleeve sections that are fitted into the hillsides on the left bank (L) and right bank (R). The overflow section 14 is located between the left and right non-overflow sections 13 and is the section through which water flows when passing over the sediment control dam 10. Furthermore, as shown in Figure 2, the dam body 11 is formed in a trapezoidal shape in a longitudinal section along the flow of the valley, for example, and the downstream slope is set to 1:0.2. 【0018】 As shown in Figure 1, the forecourt protection structure 16 includes, for example, a splashing platform 17, a secondary embankment 18, and a side wall revetment 19. The water-repellent section 17 is the part that receives the water that falls through the overflow section 14. In this embodiment, the foreyard protection structure 16 is constructed of soil cement as described above, but the materials used to construct, for example, the riprap 17, the secondary dam 18, and the side wall revetment 19 can be arbitrarily set, and all or part of them may be constructed with concrete instead of soil cement, or they may be constructed using other materials. Furthermore, whether or not reinforcing members are placed inside the foreyard protection structure 16 (riprap 17, secondary dam 18, side wall revetment 19) can be arbitrarily set. 【0019】 The access road 20 includes a downstream slope (downstream road) 22 located in the downstream area D of the sediment control dam 10, and an upstream slope (upstream road) 24 formed toward the sediment accumulation area S formed in the upstream area U of the sediment control dam 10. The downstream slope (downstream road) 22 is located in the downstream area D of the sediment control dam 10 and is formed by connecting the setting position of the streambed, which is connected to, for example, a forest road, with the non-overflow section 13 of the crest 12. In this specification, the term "sedimentation area S" may also be used to refer to an area where soil, rocks, and gravel are trapped without the accumulation of sand. 【0020】 Furthermore, in this embodiment, the downstream end of the downstream slope (downstream road) 22 is set at a lower position (lower elevation) than the top surface 12 of the downstream area D, which is the streambed (or riverbed). Furthermore, the downstream slope (downstream road) 22 is formed in a straight line from the downstream end toward the top 12 when viewed from above, and the top 22T, which is the upstream end (the position corresponding to the top 12), is formed to be slightly higher than the non-overflow section 13. Furthermore, it is possible to ascend from the set position to the non-overflow section 13 of the top surface 12 using the downstream slope (downstream road) 22. The shape of the top surface 22T may be set arbitrarily, and it may be set flush with the non-overflow section 13. Furthermore, the downstream slope (downstream road) 22 may have a landing area at an intermediate position, as shown in Figure 2. 【0021】 Furthermore, the downstream slope (downstream road) 22 comprises a left downstream slope (left downstream road 22L) formed on the left bank side of the stream, and a right downstream slope (right downstream road) 22R formed on the right bank side. In other words, the downstream slope (downstream road) 22 is formed on both the left and right banks (left bank L, right bank R) on either side of the water flowing through the overflow section 14 of the weir body 10 or across the streambed. 【0022】 Furthermore, the downstream slope (left downstream road) 22L and the right downstream slope (right downstream road) 22R are set to a width that allows transport vehicles and heavy machinery used for removing rocks to pass through and transport the removed soil to the soil disposal site. Furthermore, the downstream slope (left downstream road) 22L and the right downstream slope (right downstream road) 22R will have safety fences or guardrails (not shown) installed at both ends to prevent falls. Furthermore, the width and dimensions of the downstream slope (left downstream road) 22L and the right downstream slope (right downstream road) 22R, as well as whether or not to install fall prevention fences and guardrails, and whether to install them on the left or right side, may be set arbitrarily. 【0023】 The upstream slope (upstream road) 24 is located in the upstream area U of the sediment control dam 10 and is formed by connecting the sediment control dam 10, the rock removal work area set up in the sediment accumulation area S, and the non-overflow section 13 of the crest 12. Furthermore, the upstream slope (upstream road) 24 is curved when viewed in plan from, for example, the top surface 12 toward the stream, and is formed in a direction that gradually approaches the stream. Note that the shape of the upstream slope (upstream road) 24 may be set arbitrarily. Furthermore, heavy machinery and transport vehicles for rock removal can be moved from the non-overflow section 13 to the rock removal work area (not shown). 【0024】 Furthermore, the upstream slope (upstream road) 24 comprises a left upstream slope (left upstream road) 24L formed on the left bank L of the stream G, and a right upstream slope (right upstream road) 22R formed on the right bank R. In other words, the upstream slope (upstream road) 24 is constructed on both the left and right banks (left bank L, right bank R) on either side of the water flowing through the overflow section 14 of the weir body 10 or across the streambed. 【0025】 The materials used to construct the access road 20 may be determined arbitrarily. In this embodiment, as described above, the access road 20 is constructed of the same soil cement as the sediment control dam 10. Alternatively, it may be constructed using concrete or earth embankment instead of soil cement, or reinforcing members such as structural steel may be placed inside. 【0026】 Furthermore, when constructing the downstream slope (downstream road) 22 by embankment, it is preferable that erosion control measures be taken to prevent erosion by rainwater, for example. Specifically, for example, steel slag or the like can be laid and compacted on the road surface, or asphalt paving can be applied. Furthermore, although we have described the case in which a protective wall is installed on the side of the forecourt protection structure 16 to prevent it from being buried and affected, whether or not to install a protective wall is a matter of discretion. 【0027】 According to the management road-integrated sediment control dam (sediment control dam structure) 100 of the first embodiment, by integrating the management road 20 with the sediment control dam 10, heavy machinery, trucks, and other means of transport can be easily moved to the sediment accumulation area S with a simple structure, and the sediment accumulated in the sediment accumulation area S can be efficiently removed. 【0028】 Furthermore, with the integrated management road type sediment control dam (sediment control dam structure) 100, there is no need to excavate the slope of the mountainside on a large scale to form cut soil and lay a management road, thus reducing the construction costs and shortening the construction period for installing the management road. Furthermore, since there is no need to excavate large areas of soil, it becomes easier to dispose of the soil generated by the cutting. 【0029】 Furthermore, the integrated management road type sediment control dam (sediment control dam structure) 100 is equipped with a downstream slope (downstream road) 22, which increases the bearing capacity (resistance) against downstream forces acting on the dam body 11. 【0030】 A modified example of the sediment control dam structure according to the first embodiment will be described below with reference to Figure 4. Figure 4 is a conceptual diagram illustrating the schematic configuration of the crane installation section of a management road-integrated sediment control dam (sediment control dam structure) according to a modified example of the first embodiment. In Figure 4, reference numeral 100A indicates a modified example of a management road-integrated sediment control dam (sediment control dam structure), and reference numeral 30 indicates the crane installation section. 【0031】 As shown in Figure 4, the integrated management road sediment control dam (sediment control dam structure) 100A includes, for example, a sediment control dam 10 and a downstream slope (downstream road) 22 which is a management road 20. The management road integrated sediment control dam (sediment control dam structure) 100A differs from the management road integrated sediment control dam 100 according to the first embodiment in that the management road integrated sediment control dam 100A does not have the upstream slope (upstream road) 24 of the management road integrated sediment control dam (sediment control dam structure) 100, but has a crane installation section 30. Other aspects are the same as the management road integrated sediment control dam 100, so the same reference numerals are used and their explanations are omitted. 【0032】 In this embodiment, the crane installation section 30 is positioned at the top 22T of the downstream slope (downstream road) 22, corresponding to the top surface 12. Furthermore, the crane installation section 30 is equipped with four installation anchor bolts 31, for example, installed at the top 22T. The configuration of the crane installation section may be set arbitrarily, and instead of the installation anchor bolts 31, or in combination with the installation anchor bolts 31, a combination of structural steel such as square pipes, H-beams, channels, or other support members may be used. 【0033】 According to the modified version of the first embodiment, the integrated management road type sediment control dam (sediment control dam structure) 100A is equipped with a crane installation section 30, which allows for the efficient installation of a rock removal crane (not shown) on the sediment control dam 10. As a result, even if the integrated sediment control dam (sediment control dam structure) 100A does not have an upstream slope (upstream road), it is possible to efficiently remove sediment from the sediment accumulation area S. 【0034】 Furthermore, in a management road-integrated sediment control dam (sediment control dam structure) equipped with an upstream slope (upstream road) 24, if the means of transport, etc. are equipped with an upstream slope (upstream road), the crane installation section 30 may be placed in a location that does not hinder movement to the upstream slope (upstream management road) (for example, a non-overflow section 12 near the management road). 【0035】 Hereinafter, with reference to Figure 5, a second embodiment of the present invention, a road-integrated sediment control dam (sediment control dam structure), will be described. Figure 5 is a conceptual diagram illustrating the general configuration of the dam body as seen from the downstream side, illustrating the management road-integrated sediment control dam (sediment control dam structure) according to the second embodiment. In Figure 5, reference numeral 110 denotes a sediment control dam integrated with a management road (sediment control dam structure), and reference numeral 10A denotes a sediment control dam. 【0036】 The difference between the management road-integrated sediment control dam (sediment control dam structure) 110 of the second embodiment and the management road-integrated sediment control dam (sediment control dam structure) 100 of the first embodiment is that it is equipped with a permeable dam body 111 instead of an impermeable dam body 11. Other aspects are the same as in the first embodiment, so the same reference numerals are used and their explanation is omitted. 【0037】 The integrated erosion control dam (erosion control dam structure) 110 for management roads includes, for example, an erosion control dam 10B and a management road 20. The sediment control dam 10B comprises, for example, a dam body 111 and a steel frame 115. The dam body 111 includes, for example, sleeve sections 111L and 111R fitted into the left bank L and right bank R, respectively, with a crest (non-overflow section) 112 formed above the sleeve sections 111L and 111R. A slit (opening) 114 is formed between the sleeve sections 111L and 111R, and a steel frame 115 is placed in the slit (opening) 114. The presence or absence of the steel frame in the slit (opening) 114 and the shape of the steel frame may be set arbitrarily. 【0038】 The steel frame 115 is constructed, for example, by combining structural steel, and comprises horizontal members 115H formed in the horizontal direction and vertical support members 115V erected from the ground at an angle approximately vertical or upstream and connected to the horizontal members, and the steel frame 115 has sufficient strength to withstand debris flows. The water then passes through the slit (opening) 114, separating the water from the soil and gravel in the debris flow, and the soil and gravel are then trapped by the frame 115. 【0039】 The access road (not shown) is formed by connecting the crest (non-overflow section) 112 with the downstream end of the gorge (streambed) located in the downstream area. According to the management road-integrated sediment control dam (sediment control dam structure) 110 of the second embodiment, sediment and gravel can be efficiently captured without storing water, and the captured sediment and gravel can be efficiently removed by the management road 20. 【0040】 It should be noted that the present invention is not limited to the embodiments described above and can be modified in various ways. For example, in the above embodiment, the case in which the management road-integrated sediment control dam (sediment control dam structure) 100, 100A, and 110 are installed in a stream G where water is constantly flowing was described. However, the location where the management road-integrated sediment control dam (sediment control dam structure) is installed may be applied to various sediment control dams where it is necessary to remove sediment, such as in still streams or small streams. 【0041】 Furthermore, although the above embodiment described a case in which the management road-integrated sediment control dam (sediment control dam structure) 100 is equipped with a sediment control dam 10 having a foreyard protection structure 16, whether or not to provide a foreyard protection structure 16 may be set arbitrarily, and the configuration of the foreyard protection structure may also be set arbitrarily. 【0042】 Furthermore, in the above embodiment, we have described a case in which the management road-integrated sediment control dam (sediment control dam structure) 100 is equipped with a management road 20 having a downstream road 22 and an upstream road 24 on both banks (left bank L, right bank R) of the valley G. However, the configuration of the management road 20 may be set arbitrarily. For example, the management road 20 may be provided on one of the left bank L and the right bank R, or the management road may be equipped with three or more (multiple) downstream roads, or the downstream slope of the dam body 11 may be set to a gentle slope that allows vehicles to move, and the management road may be configured accordingly. In addition, if a foreyard protection structure 16 is provided, the management road may have a portion that passes over the foreyard protection structure 16. Furthermore, the top 22T of the downstream slope (downstream management road) 22 Non-overflow area Although the case where it is formed as described in 13, the position of the top 22T can be set arbitrarily, and it may be set in the overflow section 14 or in a part that temporarily becomes a non-overflow section depending on the weather. 【0043】 Furthermore, in the above embodiment, when the sediment control dam 10 is equipped with a foreyard protection structure 16 and the management road 20 is constructed by embankment, it is preferable to install a protective wall on the side of the management road 20 facing the foreyard protection structure 16 to prevent the foreyard protection structure 16 from being buried and thus affecting the foreyard protection structure 16. 【0044】 Furthermore, in the above embodiment, the case was described in which the downstream end of the downstream slope (downstream road) 22 is set in the downstream area D of the sediment control dam 10, which is on a streambed lower than the crest 12. However, for example, the downstream end of the downstream slope (downstream road) 22 may be set at a position equivalent to or higher than the crest 12, such as on the slope or riverbed of the stream G in the downstream area D. In other words, the downstream road 22 does not need to be a slope that ascends from a low point in the downstream area D towards the crest 12. 【0045】 Furthermore, although the above embodiment described a case in which the management road-integrated sediment control dam (sediment control dam structure) 100 is equipped with an upstream slope (upstream road) 24, whether or not to provide an upstream slope (upstream road) 24 may be set arbitrarily. 【0046】 Furthermore, although the above embodiment described a case in which the sediment control dam 10 and the access road 20 are constructed of soil cement (the same material), the material composition of the access road-integrated sediment control dam (sediment control dam structure) 100 may be set arbitrarily. For example, the integrated erosion control dam (erosion control dam structure) 100 for management roads may be constructed of concrete, or a combination of soil cement and concrete may be used for construction. Alternatively, one of the erosion control dam 10 and the management road 20 may be constructed of soil cement, and the other of the dam may be constructed of concrete. 【0047】 Furthermore, although the above embodiment described a case in which the surface of the access road 20 is covered with asphalt, the construction of the surface of the access road 20 may be set arbitrarily. 【0048】 In the above embodiment, the case in which the upstream slope (upstream road) 24 is connected to a rock removal work area installed at one location on each of the left and right banks of the sediment accumulation area S was described. However, the position of the upstream end of the upstream slope (upstream road) 24 may be set arbitrarily, and it may be connected to rock removal work areas installed at multiple locations in the sediment accumulation area S, or it may be configured to extend toward any location in a predetermined section of the sediment accumulation area S. [Explanation of Symbols] 【0049】 10, 10A, 10B Sediment control dam 11 Dam body 12 Top surface 13 Non-overflow area 14 Overflow section 16 Front garden protection works 17 Water beating 18 Sub-levee 19 Side wall revetment 20 Administrative roads 22 Downstream slope (downstream road) 22L Left downstream slope (left downstream road) 22R Right downstream slope (right downstream road) 24 Upstream slope (upstream road) 24L Left upstream slope (left upstream road) 24R Right-right overflow slope (right-right overflow road) 30 Crane installation section 31. Anchors for crane installation 100, 100A, 110 Integrated sediment control dam for management roads (sediment control dam structure) 111 Dam body 111L sleeve part 111R sleeve part 114 Slit (opening) 115 Configuration Frames G Valley W water flow S Sediment area L left bank R right bank U Upstream D Downstream region

Claims

[Claim 1] A sediment control dam installed in a stream or river to prevent soil, rocks, and gravel from flowing downstream, A maintenance road used for removing and transporting soil and rocks accumulated in the sediment deposit area of ​​the aforementioned sediment control dam, Equipped with, The aforementioned access road is, The dam has a downstream road connecting the downstream area of ​​the dam and the top of the dam. A sediment control dam structure characterized by the following. [Claim 2] The aforementioned downstream road is The downstream region and the non-overflow portion of the top surface are formed to connect the two. The sediment control dam structure according to feature 1. [Claim 3] The aforementioned access road is, It is formed extending from the aforementioned top surface toward the upstream region and includes an upstream road for transporting the removed soil, rocks, and gravel. A sediment control dam structure according to claim 1 or 2, characterized by the features described herein. [Claim 4] The aforementioned access road is made of the same material as the aforementioned sediment control dam. A sediment control dam structure according to claim 1 or 2, characterized by the features described herein. [Claim 5] The aforementioned sediment control dam is equipped with a forecourt protection structure. The aforementioned downstream road is constructed of an embankment and includes a protective wall section installed on the side of the aforementioned forecourt protection structure. A sediment control dam structure according to claim 1 or 2, characterized by the features described herein. [Claim 6] The top surface is equipped with a crane installation section, A crane for removing rocks can be attached to the aforementioned crane installation section. A sediment control dam structure according to claim 1 or 2, characterized by the features described herein.

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